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Histomorphologic features of the nasal cavity of pigs exposed to Pasteurella multocida type-D dermonecrotic toxin.
1993
Ghoshal N.G. | Niyo Y.
Microscopic examination of the nasal mucosa of clinically normal specific-pathogen-free pigs and of toxicogenic type-D Pasteurella multocida toxin challenge-exposed specific-pathogen-free pigs indicated that the surface epithelium in pigs of both groups was microscopically normal; erosions or appreciable inflammatory changes were not evident. In pigs of both groups and in aU 3 regions of the nasal cavity, the endothelial lining of all blood vessels appeared normal without detectable changes to the walls at postinoculation day 10. Vascular injury in the cartilage or the bone was not discernible in control or challenge-exposed pigs. There were marked differences in the osseous structures of the conchae when the 2 groups were compared. In control pigs, active bone formation and remodeling were observed, and the septal cartilage was normal. In toxin challenge-exposed pigs, there likewise was normal bone formation and remodeling in the vestibular region, and the septal cartilage was normal. In marked contrast, conspicuous changes were observed in the osseous core of the conchae of the respiratory and, sometimes, the olfactory regions. These changes consisted of bone necrosis and resorption by large numbers of osteoclasts with variable replacement by dense mesenchymal stroma, which resulted in conchal atrophy. In the absence of any discernible damage or injury (angiopathy) to the nasal vessels, it appears that the action of the dermonecrotoxin of P multocida serotype D is on the most active osteoblasts and the associated organic matrix of the bone, with subsequent disruption of normal bone formation and remodeling of the nasal conchae.
Afficher plus [+] Moins [-]In vitro susceptibility of Actinobacillus pleuropneumoniae strains to 42 antimicrobial agents.
1993
Gutierrez C.B. | Piriz S. | Vadillo S. | Rodriguez Ferri E.F.
Minimal inhibitory concentration of 42 antimicrobial agents was determined against 57 field strains of Actinobacillus pleuropneumoniae isolated from pigs in Spain. Penicillins, aminoglycosides, and tetracyclines had irregular activity; ticarcillin, tobramycin, and doxycycline were the most active of each group, respectively. Macrolides, vancomycin, dapsone, and tiamulin, to which strains had high rate of resistance, were almost ineffective. Thiamphenicol, colistin, rifampin, fosfomycin, mupirocin, and metronidazole had good activity, with resistance ranging between 0 and 8.8%. Finally, cephalosporins (except cephalexin) and quinolones especially ciprofloxacin, enrofloxacin, and sparfloxacin) were the most active antibiotics against A pleuropneumoniae.
Afficher plus [+] Moins [-]Resuscitation of anesthetized endotoxemic pigs by use of hypertonic saline solution containing dextran.
1993
Hellyer P.W. | Meyer R.E. | Olson N.C.
We evaluated the biochemical and hemodynamic response to hypertonic saline solution plus dextran in isoflurane-anesthetized pigs infused IV with Escherichia coli endotoxin (5 micrograms/kg of body weight for 0 to 1 hour + 2 micrograms/kg for 1 to 4 hours). After 120 minutes of endotoxemia, pigs were treated with a bolus (4 ml/kg over 3 minutes) of either normal saline solution (NSS; 0.9% NaCl), or hypertonic saline solution plus dextran (HSSD; 7.5% NaCl + 6% dextran-70). Administration of HSSD significantly (P < 0.05) increased serum osmolality and concentrations of sodium and chloride for approximately 2 hours during endotoxemia. Plasma total protein concentration decreased significantly (P < 0.05) for 2 hours after treatment with HSSD, indicating hemodilution and increased plasma volume. Although HSSD transiently increased cardiac index (CI) for approximately 15 minutes, this effect was not sustained; however, the endotoxin-induced decrease in CI was ameliorated from 120 to 180 minutes. In pigs of the endotoxin + NSS group from 180 to 240 minutes, CI decreased significantly (P < 0.05), compared with baseline and control values. The endotoxin-induced increases in mean pulmonary arterial pressure and pulmonary vascular resistance were not attenuated by HSSD. At 135 minutes, total peripheral vascular resistance was transiently lower (for approx 15 minutes) in pigs treated with HSSD, compared with control pigs. The endotoxin-induced increase in plasma lactate concentration was not attenuated by HSSD, indicating continued peripheral O2 debt. We conclude that, despite sustained increases in serum osmolality and concentrations of sodium and chloride, HSSD has only transiently beneficial cardiopulmonary effects during endotoxemia in pigs.
Afficher plus [+] Moins [-]A histopathological study on porcine cysticercosis.
1993
Shin T.K. | Kim S.H.
Morphopathogenesis of the abscess induced by Dermatophilus like microorganism in mice.
1993
Ha C.S. | Park U.B.
Effect of filtrates of Serpulina (Treponema) hyodysenteriae on the epithelium in colonic loops in swine
1993
Kang, B.H. (Korea Research Institute of Chemical Technology, Taejon (Korea Republic). Toxicology Research Center) | Olander, H.J. (California University, California (USA). School of Veterinary Medicine)
The responsiveness to amitraz in isolated porcine myometrial strips
1993
Shin, D.H. (Chonnam National University, Kwangju (Korea Republic). College of Veterinary Medicine)
Typing of Staphylococcus hyicus subsp. hyicus by staphylococcin sensitivity
1993
Park, C.K. (Kyungpook National University, Taegu (Korea Republic). College of Veterinary Medicine)
Survey on porcine eperythrozoonosis in Korea
1993
Chon, Y. | Chang, H. (Rural Development Administration, Anyang (Korea Republic). Veterinary Research Institute)
The (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) colorimetric assay for the quantitation of Actinobacillus pleuropneumoniae cytotoxin
1993
Chung, W.B. | Backstrom, L.R. | McDonald, J. | Collins, M.T.